// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package elasticsearch

import (
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
)

func TestExponentialBackoff(t *testing.T) {
	init := 2 * time.Second
	backoffCfg := BackoffConfig{
		Init: init,
		Max:  time.Minute,
	}
	backoffFn := exponentialBackoff(backoffCfg)
	assert.Equal(t, init, backoffFn(1))
	assert.Equal(t, 4*time.Second, backoffFn(2))
	assert.Equal(t, 8*time.Second, backoffFn(3))
	assert.Equal(t, 16*time.Second, backoffFn(4))
	assert.Equal(t, 32*time.Second, backoffFn(5))
	assert.Equal(t, time.Minute, backoffFn(20))
}
